This application is related to and claims priority from Japanese Patent Application No. 2001-45290 filed on Feb. 21, 2001, the content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a charging control system for a vehicle air conditioner and for a vehicle battery, which suitably controls a residual charge amount of the vehicle battery.
2. Description of Related Art
In a vehicle such as a hybrid vehicle having a driving motor, when a residual charge amount of a battery for supplying electrical power to the driving motor is small, an over-discharge may be occurred in the battery if the battery is continuously greatly discharged to vehicle electrical equipment, and the driving motor sometimes cannot drive the vehicle.
In an air conditioner for an electrical vehicle described in JP-A-8-244439, plural electrical heaters used as an auxiliary heating source are combined with a heat pump cycle including an electrical compressor. That is, in the air conditioner, a residual charge amount of a battery is detected, and a rotation speed of the electrical compressor is reduced in accordance with the reduction of the detected residual charge amount. Further, among the plural electrical heaters, the number of electrical heaters to be operated is reduced in accordance with the reduction of the detected residual charge amount. Thus, electrical power consumed for the air-conditioner is reduced in accordance with the reduction of the residual charge amount of the battery, thereby increasing a travelling distance of the electrical vehicle.
In the vehicle air conditioner, the other various electrical devices such as an interior electrical blower and an exterior electrical blower are provided in addition to the electrical compressor and the electrical heaters. Therefore, the residual charge amount of the battery is also affected by the operation of the other various electrical devices. However, this document does not specifically disclose a method for electrically controlling the other various electrical devices.
In view of the foregoing problems, it is an object of the present invention to provide a charging control system for a vehicle, which suitably controls a residual charge amount of a battery while air-conditioning performance of a vehicle air conditioner can be improved.
According to the present invention, in a vehicle having a battery for supplying electrical power to plural air-conditioning electrical devices and a generator for charging the battery, when a residual charge amount of the battery is reduced to a first predetermined amount, operations of the plural air-conditioning electrical devices are stopped, a power generation command is outputted to a generator for charging the battery. Further, when the residual charge amount is increased to be larger than the first predetermined amount after the plural air-conditioning electrical devices are stopped, the plural air-conditioning electrical devices are re-started at different start times. Alternatively, when the residual charge amount is increased to be larger than the first predetermined amount after the plural air-conditioning electrical devices are stopped, the plural air-conditioning electrical devices are re-started at the same time by small operation levels, respectively. Accordingly, it can prevent the residual charge amount of the battery from being reduced and the battery from being excessively discharged, thereby preventing the vehicle from being incapable of moving due to the excessive discharge of the battery. Further, after the plural air-conditioning electrical devices are re-started, power consumption of the plural air-conditioning electrical devices is not rapidly increased. Therefore, the residual charge amount of the battery is not reduced again to the first predetermined amount due to the re-starting operation of the air-conditioning electrical devices. As a result, the air-conditioning electrical devices can be smoothly re-started while it can restrict the operation of the air-conditioning electrical devices from being re-stopped due to the control of the residual charge amount of the battery.
Preferably, when the residual charge amount of the battery is reduced to a second predetermined amount larger than the first predetermined amount, a power generation command for operating the generator is output so that the battery is charged by the generator. That is, only in an emergency case where the residual charge amount of the battery is reduced to the first predetermined amount, the plural air-conditioning electrical devices are stopped. Accordingly, the air-conditioning prohibition operation for the plural air-conditioning electrical devices is only limited to the specific emergency case.
Preferably, after the air-conditioning electrical devices are re-started, operation levels of the air-conditioning devices are gradually increased from the small operation levels toward necessary operation levels required for performing air-conditioning operation in the passenger compartment, respectively. Therefore, it can prevent the consumption power of the air-conditioning electrical devices from being rapidly increased after the re-starting operation, while air conditioning capacity can be smoothly improved.